RAS extensions are part of ARMv8.2-A. This change enables them by introducing a

new instruction to ARM and AArch64 targets and several system registers.

Patch by: Roger Ferrer Ibanez and Oliver Stannard

Differential Revision: http://reviews.llvm.org/D20282

llvm-svn: 271670

1 files changed, 18 insertions, 0 deletions

diff --git a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index 8b231d3f7d1..b9207a02c9e 100644
--- a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -296,6 +296,9 @@ class ARMAsmParser : public MCTargetAsmParser {
   bool hasV8_1aOps() const {
     return getSTI().getFeatureBits()[ARM::HasV8_1aOps];
   }
+  bool hasRAS() const {
+    return getSTI().getFeatureBits()[ARM::FeatureRAS];
+  }
 
   void SwitchMode() {
     MCSubtargetInfo &STI = copySTI();
@@ -6512,6 +6515,20 @@ bool ARMAsmParser::validateInstruction(MCInst &Inst,
           "immediate expression for mov requires :lower16: or :upper16");
     break;
   }
+  case ARM::HINT:
+  case ARM::t2HINT: {
+    if (hasRAS()) {
+      // ESB is not predicable (pred must be AL)
+      unsigned Imm8 = Inst.getOperand(0).getImm();
+      unsigned Pred = Inst.getOperand(1).getImm();
+      if (Imm8 == 0x10 && Pred != ARMCC::AL)
+        return Error(Operands[1]->getStartLoc(), "instruction 'esb' is not "
+                                                 "predicable, but condition "
+                                                 "code specified");
+    }
+    // Without the RAS extension, this behaves as any other unallocated hint.
+    break;
+  }
   }
 
   return false;
@@ -10155,6 +10172,7 @@ static const struct {
   // FIXME: Only available in A-class, isel not predicated
   { ARM::AEK_VIRT, Feature_HasV7, {ARM::FeatureVirtualization} },
   { ARM::AEK_FP16, Feature_HasV8_2a, {ARM::FeatureFPARMv8, ARM::FeatureFullFP16} },
+  { ARM::AEK_RAS, Feature_HasV8, {ARM::FeatureRAS} },
   // FIXME: Unsupported extensions.
   { ARM::AEK_OS, Feature_None, {} },
   { ARM::AEK_IWMMXT, Feature_None, {} },